Battery adapter



FIG. 1 is a top, front perspective view of a battery adapter;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a left side elevation view thereof; and,

FIG. 7 is a rear elevation view thereof.

The broken lines shown in the drawings depict portions of the battery adapter that form no part of the claimed design. 

CLAIM The ornamental design for a battery adapter, as shown and described. 